EYBOPSIS 163 



This is an active fish, decidedly preferring clear rocky streams. 

 Breeding males were taken about Ottawa in June. It has been 

 seen to spawn in shallow running water, piling pebbles up about 

 the nest after the eggs are deposited. Spring males have the 

 front of the head and the occipital region finely tuberculate. 



Genus HYBOPSIS Agassiz 



Body robust or elongate; mouth terminal or inferior; a barbel always 

 present, terminal on the maxillary (in one species there are 2 barbels on each 

 side); premaxillary protractile; teeth 4-4, or 1, 4-4, 1 or 0, hooked and with 

 grinding surface narrow or obsolete; intestine short; peritoneum pale, dusky, 

 or black; dorsal rays 7 or 8; anal 6 to 8; scales 35 to 60; lateral line con- 

 tinuous. Species numerous, about 17; 5 in Illinois. A large and varied 

 group, embracing both small species from 2 x /i to 5 inches in length and larger 

 forms up to a length of 10 or 12 inches. United States east of the Rockies; 

 one species from California. 



HYBOPSIS HYOSTOMUS (Gilbert) 



Gilbert, 1884, Proc. U. S. Nat. Mus., 203 (Nocomis). 

 M. V., 64; J. & E., I, 316; L., 19 (part). 



Very small minnows with an inferior mouth, and with barbel % to 3^ as 

 long as snout, easily distinguished among Illinois Cyprinidae by their small 

 size, elongate eye, posteriorly placed mouth (tip of lower lip under first 

 nostril), and rusty- to blackish-punctulate coloration. Length of our largest 

 specimens \% inches; body moderately elongate, subfusiform, little com- 

 pressed, heaviest forward of dorsal fin; depth 4.9 to 6.2 in length; caudal 

 peduncle slender, its depth 2.5 to 2.8 in its length. Color silvery, every- 

 where more or less dusted with brownish specks; similar but larger specks, 

 suggesting rust-spots in preserved material, found on nose, suborbitals, and 

 opercles; fins all pale. Head rather long, 3.7 to 4, its width 2 to 2.1 in its 

 length; interorbital space nearly flat, 3.5 to 4 in head; eye 2.8 to 3.4, ellip- 

 tical, its long diameter l}4 to V/i times its short; nose 2.7 to 3.1, about as 

 long as eye, broad, bluntly pointed and decurved, projecting nearly half 

 its length beyond the mouth; mouth wholly inferior and horizontal, tip of 

 lower lip directly under first nostril; maxillary 3.3 to 3.8 in head, reaching 

 past front of orbit; barbel long, 2 to 3 in snout; isthmus less than pupil. 

 Teeth 4-4, rather strongly hooked, the grinding surface extremely narrow 

 or not at all developed; peritoneum silvery, with some rather coarse specks 

 upward. Dorsal fin with 8 rays, rarely 7, set about over ventrals and 

 equidistant between muzzle and base of caudal; longest dorsal ray 1.1 to 

 1.3 in head; anal rays 7 or 8, usually 7; pectorals more than % to ventrals; 

 ventrals past vent. Scales 5, 34-36, 4; 14 before dorsal; lateral line decurved. 



Sexual differences not noted, our specimens being few and probably 

 not fully grown. 



